Parasocks I had this same error, it got ok but I believe it can be for either case, first hipotetic case, which is I had, my pc got out of memory and internet since all the resources were used by windows to download and install its actualizations. I have found that there is a wupdate.exe or something like that working and consuming a lot of pc resources.

Second option is that it is a problem with your internet company you can call them(I usually find this like a waist of time though.) Other matter may be that your DNS has not being uploaded correctly but since you were able to connect here it seems ok.

I don't really know if the problem is one of those I have written since most of them should be corrected in few time.

Other problem is if you have denied permision to mozilla or to chesscube site to open/use flash which can be done in the browser properties for each site.

Sorry if this was for no help but I can't think right now of any more options if some come to my mind I will put more here.